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public:documents:raw_olap_data_formats [2012-03-20 09:45] – Jan David Molpublic:documents:raw_olap_data_formats [2017-03-08 15:27] (current) – external edit 127.0.0.1
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-===== Raw OLAP data formats ====+===== Raw OLAP data formats (obsolete) ====
  
 OLAP produces several data formats, which are intended to be replaced by their final format, such as HDF5. OLAP produces several data formats, which are intended to be replaced by their final format, such as HDF5.
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 </code> </code>
  
-The constants used can be derived from the parset through:+The constants used can be derived from the parset:
  
-|SUBBANDS|The number of subbands (beamlets) specified     |len(Oberservation.subbandList)| +<code> 
-|CHANNELS|The number of channels per subband              |Observation.channelsPerSubband|+  SUBBANDS = len(parset["Observation.subbandList"]) 
 + 
 +  if (complex voltages || coherent stokes) { 
 + 
 +    CHANNELS = parset["OLAP.CNProc_CoherentStokes.channelsPerSubband"] 
 +    if (CHANNELS == 0) CHANNELS = parset["Observation.channelsPerSubband"] 
 + 
 +  } elif (incoherent stokes) { 
 + 
 +    CHANNELS = parset["OLAP.CNProc_IncoherentStokes.channelsPerSubband"] 
 +    if (CHANNELS == 0) CHANNELS = parset["Observation.channelsPerSubband"] 
 + 
 +  } 
 +</code>
  
 The sampling rate can be derived as follows: The sampling rate can be derived as follows:
 +
 <code> <code>
   # clock frequency (f.e. 200 MHz)   # clock frequency (f.e. 200 MHz)
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   base_channel_hz = base_subband_hz / base_nrchannels   base_channel_hz = base_subband_hz / base_nrchannels
  
-  if(complex voltages) { +  if(complex voltages || coherent stokes) {
- +
-    sample_hz = base_channel_hz +
- +
-  } elif(coherent stokes) { +
- +
-    cs_nrchannels = parset["OLAP.CNProc_CoherentStokes.channelsPerSubband"] +
-    if (cs_nrchannels == 0) cs_nrchannels = base_nrchannels +
- +
-    cs_spectralintegration = base_nrchannels / cs_nrchannels+
     cs_temporalintegration = parset["OLAP.CNProc_CoherentStokes.timeIntegrationFactor"]     cs_temporalintegration = parset["OLAP.CNProc_CoherentStokes.timeIntegrationFactor"]
  
-    sample_hz = base_channel_hz / cs_temporalintegration / cs_spectralintegration+    sample_hz = base_channel_hz / cs_temporalintegration
  
   } elif(incoherent stokes) {   } elif(incoherent stokes) {
  
-    is_nrchannels = parset["OLAP.CNProc_IncoherentStokes.channelsPerSubband"] 
-    if (is_nrchannels == 0) is_nrchannels = base_nrchannels 
- 
-    is_spectralintegration = base_nrchannels / is_nrchannels 
     is_temporalintegration = parset["OLAP.CNProc_IncoherentStokes.timeIntegrationFactor"]     is_temporalintegration = parset["OLAP.CNProc_IncoherentStokes.timeIntegrationFactor"]
  
-    sample_hz = base_channel_hz / is_temporalintegration / is_spectralintegration +    sample_hz = base_channel_hz / is_temporalintegration
   }   }
          
 </code> </code>
  
-===== Before 2011-20-24 =====+===== Before 2011-10-24 =====
  
 Data can be recorded as either complex voltages (yielding X and Y polarisations) or one or more stokes. In either case, a sequence of blocks will be stored, each of which consists of a header and data. The header is defined as: Data can be recorded as either complex voltages (yielding X and Y polarisations) or one or more stokes. In either case, a sequence of blocks will be stored, each of which consists of a header and data. The header is defined as:
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 A BFRaw file starts with a file header containing the configuration: A BFRaw file starts with a file header containing the configuration:
  
-<code>+<code C>
 struct file_header struct file_header
 { {
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 After the file header, there is a series of blocks until the end of file, configured using values from the file header: After the file header, there is a series of blocks until the end of file, configured using values from the file header:
  
-<code>+<code C>
 struct block struct block
   // 0x2913D852   // 0x2913D852
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 To convert a TimeStamp-compatible int64_t to a C-readable timestamp, use To convert a TimeStamp-compatible int64_t to a C-readable timestamp, use
-<code>+<code C>
 /* clockspeed is in Hz */ /* clockspeed is in Hz */
 int64 nanoseconds = (int64) (timestamp * 1024 * 1e9 / clockspeed); int64 nanoseconds = (int64) (timestamp * 1024 * 1e9 / clockspeed);
  • Last modified: 2012-03-20 09:45
  • by Jan David Mol